im new to this forum so bear with me. im a current student at UTI getting my masters in automotive technology, ive passed my manual trans class with flying colors. im a car guy so trust me when i say i know how to work on cars, especially nissans.

my 350z has 51k on it so i decided to change the tranny oil. its a 6spd manual. everything went smooth, put in 3.5 quarts like manufacturer specs, didnt overfill, didnt under fill, everything was normal.

i let my engine warm up every time when i start it like i should, and it shifts fine...until i get onto an on-ramp for the freeway. in fourth gear around 50mph, i hear this crazy loud high pitch whine from my tranny, sounds like underneath my e-brake, in 4th, 5th, and 6th gear its very loud, unless i let off the throttle, and it goes away, push on the throttle a lil bit and it starts again. after about 45 sec to 1 min it goes away.

calls for 75w-80 spec, but i couldnt find it in the store, so i bought 75w-90. of all the brands, they only had 75w-90, so i was like what the hell, why not.

is that the problem???? help please! i dont want to kill my tranny!

 

damn someone answer the man! I have to go buy some fluids tomorrow and dont want to find myself in the same position! lol

 

OK. Cool.

 

Car guy, why do you let your engine warm up every time you start it?

 

80 or 90 weight doesnt make any different at all.

My best guess right off my head would be a bad bearing. Bad bearings usually make a whining noise.

 

pooped transmission. the whine usually means its goin south.